1. Field of the Invention
The present invention generally relates to rotary sensors and methods of determining position that utilize the rotary sensors. More specifically, the present invention relates to rotary sensors that contain code relating to bits of positional data and methods of determining position that utilize the same by sensing and encoding- the positional data.
2. Discussion of the Background
Automotive original equipment manufacturers utilize more and more electronics in automotive vehicle steering systems and assemblies. These systems include, for example, four-wheel steering, electric power assisted steering, EVO, automatic roll stability, and other like systems.
Typically, optical steering wheel angle sensors have been utilized to provide the necessary positional data -that is required by the vehicle steering systems. Conventional steering wheel angle sensors include a code wheel that is utilized to break a beam of light as the steering wheel moves during operation. This creates a series of electrical pulses that can be interpreted electronically to detect the position of the steering wheel during operation.
In general, the conventional code wheels are metal stamped or molded to provide holes therein for permitting light to pass therethrough. In addition, glass etched code wheels utilize the etched surfaces to block the light wherein clear areas on these code wheels permit light to pass through. The CCD chip utilizes an LED and code wheel arrangement as well. The CCD chip scans multiple bits of data radially rather than detecting single on/off pulses associated with the light/dark areas of the glass etched surface.
However, there are a number of problems associated with conventionally used optical steering wheel angle sensors. For example, the scanning operation of the CCD chip makes it difficult to use a standard metal stamped or molded code wheel. In addition, metal stamp code wheels have tooling limitations. The progressive dye which is used to create the metal stamped code wheel is limited to the size and spacing of the punches that are required to make the holes. Molded plastic code wheels have similar issues as well. An etched glass surface is cost prohibitive particularly if utilized in an assembly line process, such as with automotive applications.
A need, therefore exists, to provide a rotary sensor that reduces tooling costs, that provides precise and accurate positional data and that can be easily incorporated into the position sensing system, such as those relating to automotive steering wheel assemblies.
The present invention provides a rotary sensor that contains code relating to bits of positional data or information. The positional data can be sensed and encoded to determine or detect a position associated with the encoded data. The rotary sensor of the present invention can be utilized in a variety of different applications, such as those relating to automotive steering wheel assemblies. In this regard, a precise and accurate determination can be made with respect to the position of the steering wheel during operation.
To this end, in an embodiment of the present invention, a rotary position sensor is provided. The rotary position sensor includes an overmold, such as a code wheel overmold, and an applique containing code associated with bits of information wherein the applique is applied to the overmold.
In another embodiment, a method of determining a position that utilizes encoded bits of information is provided. The method includes the steps of providing a rotary position sensor that includes a code wheel overmold and an applique applied to the overmold wherein the applique contains code associated with bits of information relating to positional data; sensing and encoding the code; and determining a position associated with the encoded bits of information.
In yet another embodiment, an automotive steering wheel position sensor is provided. The steering wheel position sensor includes a code wheel overmold and a code wheel applique that is applied to the code wheel overmold wherein the code wheel applique contains a code associated with bits of information.
It is, therefore, an advantage of the present invention to provide a rotary position sensor that includes an applique which contains bits of positional data.
Another advantage of the present invention is to utilize the rotary position sensor to determine a position by sensing and encoding bits of positional data associated with the rotary position sensor.
A further advantage of the present invention is to determine the position of an automotive steering wheel during operation.
A still further advantage of the present invention is to provide a rotary position sensor that can be manufactured at reduced costs and that can be readily incorporated into a position detection system.
Yet another advantage of the present invention is to provide a rotary position sensor that can precisely and accurately determine the position of an automotive steering wheel during operation.
Additional features and advantages of the present invention are described in, and will be apparent in the detailed description of the presently preferred embodiments and from the drawings.